This invention relates generally to a wind turbine rotor blade, and more particularly, to a prefabricated sparcap of a wind turbine rotor blade.
Wind turbine blades are typically made by means of two blade shell halves, of fiber reinforced polymer. When molded the two halves are glued together along the edges and via two bracings, which prior thereto have been glued to the inner face of one the blade shell halves. The other blade shell half is then arranged on top of the bracings and glued thereto and along the edges.
The shells per se are typically made by vacuum infusion, in which evenly distributed fibers, rovings, which are fiber bundles, bands of rovings or mats, which may be felt mats of single-fibers or woven mats of fiber rovings, are layered in a mold part and covered by a vacuum bag. By creating vacuum in the cavity between the inner face of the mould part and the vacuum bag resin is sucked into and fills the cavity containing the fiber material. The used polymer is typically polyester or epoxy, and the fiber reinforcement is usually based on fiber glass.
However, the shells are relatively light and have only low rigidity. Therefore, the stiffness and rigidity as well as the buckling strength of the shells is not sufficient. To increase the strength of the rotor blades, the shells are reinforced by sparcaps which are laminated to the inner surface of the shells. Typically, the sparcaps extend substantially over the longitudinal length of the rotor blade.